Physics question (boiling in a vacuum)

I used mineral spirts to clean out my truck ac system. (flush) as well as follwed that with brake cleaner and then dry compressed air. (all I had availabnle)

Question. If any trace mineral spirits were left in the system, will these be boiled off when vacuuming with a vacuum pump?

Reply to
stryped
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Let some evaporate from a clean glass jar and see if it leaves a waxy film.

jsw

Reply to
Jim Wilkins

follwed that with brake cleaner and then dry compressed air. (all I had availabnle)

boiled off when vacuuming with a vacuum pump?

Depends on how good your vacuum is, but yes, basically. If you are concerned that a significant amount might be present in (say) a heat exchanger you can speed things up by warming it with a hot air gun. Do you have a gauge on your vacuum pump?

Reply to
newshound

Should be OK. If you can pull 400 microns or less. Mineral spirits has a low boiling point, and should clear out.

Christopher A. Young Learn more about Jesus

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Question. If any trace mineral spirits were left in the system, will these be boiled off when vacuuming with a vacuum pump?

Reply to
Stormin Mormon

follwed that with brake cleaner and then dry compressed air. (all I had availabnle)

boiled off when vacuuming with a vacuum pump?

My guage shoes 28-29 HG.

Does brake cleaner have the same low boiling point?

Reply to
stryped

"Stormin Mormon" fired this volley in news:YKFDr.70935$ snipped-for-privacy@news.usenetserver.com:

Except that "mineral spirits" is a generic name for a fairly narrow range of solvents that may or may not contain dissolved higher fractions like non-volatile oils, greases, and paraffins.

Many (not all) hardware store mineral spirits leave a waxy residue upon drying.

Lloyd

Reply to
Lloyd E. Sponenburgh

"Stormin Mormon" fired this volley in news:YKFDr.70935$ snipped-for-privacy@news.usenetserver.com:

Stormy, that was as meaningless to him as if you'd said, "use a three- pronged veebleforp to clean out the lines."

LLoyd

Reply to
Lloyd E. Sponenburgh

follwed that with brake cleaner and then dry compressed air. (all I had av= ailabnle)

e be boiled off when vacuuming with a vacuum pump?

Eventually the volatiles will go, depends on how good a vacuum you can pull. Big question is what the stuff left behind when it evaporated. I recently did my van system, took about 8 hours pumping before vacuum stabilized, 80 degree weather. I'd used some mineral spirits for a flush of some of the parts. Hopefully nothing harmful was left, just a little PAG oil residue.

Stan

Reply to
Stanley Schaefer

You need a micron gage, not an inch gage. To tell if you've got a good vacuum.

Christopher A. Young Learn more about Jesus

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My guage shoes 28-29 HG.

Does brake cleaner have the same low boiling point?

Reply to
Stormin Mormon

You know, sadly, I'm sure you are right.

Ah, well. That was a waste of plain text.

Christopher A. Young Learn more about Jesus

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Stormy, that was as meaningless to him as if you'd said, "use a three- pronged veebleforp to clean out the lines."

LLoyd

Reply to
Stormin Mormon

A 'full' vacuum reading on an inch scale would be the same as the barometer reading, assuming both gauges are accurate, which is very unlikely outside a lab.

My barometer shows 30.56" right now so 28-29" of vacuum wouldn't be very good.

The inch and micron numbers are heights of a column of mercury balanced against gas pressure, relative to either normal air pressure (29" lower) or a perfect vacuum (400 microns higher) depending on how the gauge is made. 400 microns is 0.01".

jsw

Reply to
Jim Wilkins

follwed that with brake cleaner and then dry compressed air. (all I had availabnle)

boiled off when vacuuming with a vacuum pump?

Unfortunately "hope" don't feed the bulldogs. And as you found with the vacuum pump, if any volatiles are left behind they take a long time to boil off and get carried out.

Most people don't bother pulling more than a token hard vacuum, or worse they use one of those air venturi "vacuum pumps" that isn't worth a plug nickel to "evacuate" a car system. And then they don't bother to change out the Filter/Drier and leave the old saturated one in - and wonder why the new compressor goes bad too.

They make special high-purity HVAC System flushing solvents for this purpose and they are formulated specifically to not leave any harmful deposits and to evaporate out quickly. That's NOT the time to start playing "Mister Wizard" and experimenting with the home chemistry set.

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Reply to
Bruce L. Bergman (munged human readable)

Oops, mental math mistake.

0.016" (0.015748")
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jsw
Reply to
Jim Wilkins

follwed that with brake cleaner and then dry compressed air. (all I had availabnle)

be boiled off when vacuuming with a vacuum pump?

I take it, they are "less than sub-optimal"?

Reply to
pyotr filipivich

I stopped reading when it became aparent that you thought an inch gage could read vacuums.

Christopher A. Young Learn more about Jesus

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Oops, mental math mistake.

0.016" (0.015748")
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jsw
Reply to
Stormin Mormon

"Stormin Mormon" wrote in news:eMQDr.55131$F% snipped-for-privacy@news.usenetserver.com:

What makes you think it can't?

Reply to
Doug Miller

Yeah, I noticed that but figured you were thinking the other way (microinches to mm)

Reply to
Rick

Gunner Asch on Tue, 19 Jun 2012 00:09:53 -0700 typed in rec.crafts.metalworking the following:

follwed that with brake cleaner and then dry compressed air. (all I had availabnle)

these be boiled off when vacuuming with a vacuum pump?

I will keep that in mind for this summer's project.

(Sheesh. Even I know that WD-40 is _not_ a lubricant, _or_ a solvent.)

Reply to
pyotr filipivich

I'll set up four systems. Two will have a 400 micron vacuum, two will have

1,000 micron vacuum. Use your inch gage to tell which is which.

Christopher A. Young Learn more about Jesus

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What makes you think it can't?

Reply to
Stormin Mormon

There's no rule that inch-graduated gauges have to be crude.

My inch gauge is a Dwyer model 2001 like the top left. It displays the draft of my wood stove:

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One minor division is 0.02" of Water Column, or ~0.0015" (~38 microns) of mercury. So the 600 micron difference would show plainly at around

3/10 of full scale.

jsw

Reply to
Jim Wilkins

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